Definitions

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The embryonic shell, or first chamber, of ammonites and other cephalopods.

from the GNU version of the Collaborative International Dictionary of English

  • n. The embryonic shell, or first chamber, of ammonites and other cephalopods.

from The Century Dictionary and Cyclopedia

  • n. The embryonal or primitive shell of an ammonoid cephalopod. Owen. Also called embryo-sac, oviccll, and ovisac.
  • n. The apical whorl of a gastropod shell.

Etymologies

proto- +‎ conch (Wiktionary)

Examples

  • I'd be very interested in reading any studies that have examined the strength of genetic separation in examples like this same family, similar shell form, radically different protoconch.

    A fossil snail fits in between, or, maybe not

  • The fine spiral lines of the protoconch are more likely to represent the still developing mantle anatomy of the snail embryo at the time of the secretion of its embryonic shell.

    A fossil snail fits in between, or, maybe not

  • There are very many such examples in the Australian Charopidae and the normal practice which I agree with is to regard such strong protoconch differences as automatically significant at generic level in view of the unlikelihood that there is much evolutionary pressure affecting protoconch fsculpture.

    A fossil snail fits in between, or, maybe not

  • However, one significant trait distinguishes B. gymnesica from both Mastus and Napaeus: the protoconch, or the embryonic whorls, of Balearena have spiral lines on bottom halves of whorls, whereas the Mastus and Napaeus protoconches are always devoid of such microsculpture.

    A fossil snail fits in between, or, maybe not

  • Balearena gymnesica, enture shell 1 and protoconch.

    A fossil snail fits in between, or, maybe not

  • Growth: Even before the snail hatches, it has formed a single small whorl around itself known as a protoconch.

    CreationWiki - Recent changes [en]

  • Even before the snail hatches, it has formed a single small whorl around itself known as a protoconch.

    CreationWiki - Recent changes [en]

  • As Altaba also notes, the protoconch microsculpture probably doesn’t have anything to do with burrowing, or for that matter, have any function at all.

    A fossil snail fits in between, or, maybe not

Comments

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  • Fun word! Weird, though--when I look at it on screen, I want to add even more Os to pronounce it properly. Protoconoch? Protooconch?

    *slapping self upside the head*

    December 20, 2007

  • The embryonic shell of a gastropod.

    December 20, 2007